The invention relates to flow control and more particularly, to the universal control of fluid flow and injected fluids in valves by devices such as Luer fittings, plastic cannulas and needles, both blunt and sharp.
It often is desirable to control the flow of fluids such as liquids and gases. A common device for that purpose is a valve. The valve functions by the deflection of an elastomeric element towards and away from a valve seat. The deflection is towards the valve seat in order to prevent flow, and away from the seat to permit flow.
In some cases the control of fluid flow is with respect to a multiplicity of channels that have varying degrees of convergence with one another. A typical multiplicating arrangement makes use of connectors which permit the intercalation of flow channels as desired.
An illustrative prior art valve that controls flow is set forth in U.S. Pat. No. 4,610,276 ("'276") which issued Sep. 9, 1986. This patent discloses a flow control valve with a main channel for the through-flow of fluid and a branch channel connected to the main channel at an intermediate position. The valve includes a diaphragm for controlling the flow. The diaphragm is clamped and bowed under pressure into the inlet channel. The application of pressure to the diaphragm assures the sealing of the channel.
While the diaphragm of the '276 patent operates properly in most cases, there is the possibility that the diaphragm will fail to seat properly.
Another valve arrangement is disclosed in U.S. Pat. No. 4,874,369 which issued Oct. 17, 1989. This arrangement employs a duck-bill valve in a configuration that is complex, costly and difficult to manufacture. In addition, duck-bill valves of the type contemplated by the '369 patent have proved to be unreliable in practice, with such difficulties as failure to seal properly.
Other arrangements which relate to the control of fluid flow are disclosed in Osborne U.S. Pat. No. 2,270,468; Goott et al U.S. Pat. No. 3,370,305; Craft U.S. Pat. No. 3,457,933; Rosenberg U.S. Pat. Nos. 3,572,375, 3,650,093 and 3,710,942; Bobo U.S. Pat. No. 3,886,937; Melnick U.S. Pat. No. 3,891,000; Mittleman U.S. Pat. Nos. 4,000,740 and 4,405,316; Stevens U.S. Pat. No. 4,000,739; Zedes et al U.S. Pat. No. 4,005,710; Mittleman et al U.S. Pat. Nos. 4,048,996 and 4,133,441; Rushkie et al U.S. Pat. No. 4,222,407; Sheehan et al U.S. Pat. No. 4,294,249; Spademan U.S. Pat. No. 4,338,934; Paradis U.S. Pat. No. 4,415,003; Spector et al U.S. Pat. No. 4,424,833; Edwards et al U.S. Pat. No. 4,566,493; Goodell U.S. Pat. No. 4,596,265; Suzuki et al U.S. Pat. No. 4,610,674 and Holtermann et al 4,958,661; EPO 0109903; France 2004771 and UK 2033230. None of these arrangements provide the advantages of the invention.
In addition, all of the foregoing valves require the presence of fluid pressure in order to operate the diaphragm, either by exerting pressure to open the diaphragm or by using reverse pressure to close the diaphragm. In some cases it is desirable to be able to act upon the diaphragm by using other than fluid pressure. Thus, a user may want to actuate the diaphragm independently of the presence of fluid pressure, in preparation for anticipated fluid flow. In other cases, it is desirable to maintain a diaphragm in its open position for a prescribed interval of time independently of whether fluid flow is present.
Another consideration that applies in the use of flow control devices is that the fittings used with the devices vary in tolerances. As a result, flow control valves are employed with a variety of fittings. A flow control valve that is suitable for a particular fitting may not function in the same way with a different fitting, even if the fitting is of the same general type, because of tolerance variations.
A further consideration is the need for multipurpose valves which can be used with syringes, such as those with Luer fittings, plastic cannulas and steel needles, whether blunt or sharp.
Accordingly, it is an object of the invention to enhance the control that can be achieved over fluid flow. Another object is to provide a facility for acting upon the diaphragm by using other than fluid pressure. A related object is to permit a user to actuate the diaphragm independently of the presence of fluid pressure, in preparation for anticipated fluid flow.
Still another object is to maintain a diaphragm in its open position for a prescribed interval of time independently of whether fluid flow is present.
A further object is to facilitate the use of flow control devices with fittings that vary in tolerance. A related object is to employ flow control valves with a variety of fittings. Still another related object is to permit a flow control valve that is suitable for a particular fitting to function in the same way with a different fitting, even if the fitting is of the same general type, because of tolerance variations.
A still further object is to achieve greater reliability over valve operation than is achievable by clamped diaphragms and duck-bill valves.
Yet another object is to achieve precision control at reduced cost and simplification.